Apparatus and methods for placing a managed heap

Abstract

Methods and apparatus are disclosed to intelligently place a managed heap in a memory. An example method disclosed herein identifies a current boundary of a static data region in memory, and sets a lower boundary of the managed heap at an address located a safeguard distance above the identified current boundary of the static data region in memory. Other embodiments may be described and claimed.

1. A method of placing a managed heap in a memory comprising:
 identifying a current boundary of a static data region in the memory; and 
 setting a lower boundary of the managed heap at an address located a safeguard distance above the current boundary of the static data region in the memory. 
 
     
     
       2. A method as defined in  claim 1  wherein the lower boundary of the managed heap is set such that a machine accessible instruction within the managed heap addresses the static data region using an immediate value. 
     
     
       3. A method as defined in  claim 1  wherein the lower boundary of the managed heap is set such that an immediate value of a pointer to an address in the managed heap is constructed in two instructions. 
     
     
       4. A method as defined in  claim 1  wherein the lower boundary of the managed heap is set such that an address within a code segment of the memory is accessed using a direct branch machine accessible instruction in the managed heap. 
     
     
       5. A method as defined in  claim 1  wherein identifying the current upper boundary of the static data region comprises determining the current boundary using binary image introspection. 
     
     
       6. A method as defined in  claim 1  wherein identifying the current upper boundary of the static data region comprises determining the current upper boundary using a system call. 
     
     
       7. A method as defined in  claim 1  wherein the safeguard distance is larger than a maximum growth amount of the static data region. 
     
     
       8. A method as defined in  claim 1  wherein setting a lower boundary of the managed heap comprises summing a memory address of the current boundary of the static data region, and a maximum growth amount of the static data region. 
     
     
       9. A method as defined in  claim 1  wherein setting the lower boundary of the managed heap is performed during a runtime initialization phase. 
     
     
       10. A method as defined in  claim 1  further comprising generating a direct branch from Just-in Time code located in the managed heap to virtual machine code located in a static code segment. 
     
     
       11. A method as defined in  claim 1  further comprising compressing a managed pointer to an address in the managed heap. 
     
     
       12. A method as defined in  claim 11  wherein compressing the managed pointer comprises:
 decomposing the managed pointer into a predetermined base value and an offset value; and 
 storing the offset value. 
 
     
     
       13. A method as defined in  claim 12  wherein storing the offset value comprises storing all but the last two bits of the offset value. 
     
     
       14. A method as defined in  claim 12  wherein the managed pointer points from a first address in the managed heap to a second address in the managed heap. 
     
     
       15. A method as defined in  claim 12  wherein the managed pointer points from an address in the managed heap to an address in the static data region. 
     
     
       16. A method as defined in  claim 12  wherein a predetermined number of bits of the base are combined with a predetermined number of bits of the offset to address the managed heap. 
     
     
       17. A method as define in  claim 1  further comprising constructing a managed pointer to an address in the managed heap. 
     
     
       18. A method as defined in  claim 17  wherein constructing the managed pointer comprises constructing the managed pointer from a predetermined base and an offset value. 
     
     
       19. A method as defined in  claim 18  further comprising adding two bits to the offset value. 
     
     
       20. An apparatus to place a managed heap in a memory comprising:
 a boundary locator to identify a current boundary of a static data region in the memory; and, 
 a heap placement engine to set a lower boundary of the managed heap at an address located a safeguard distance above the current boundary. 
 
     
     
       21. An apparatus as defined in  claim 20  wherein the safeguard distance is larger than a maximum growth amount of the static data region. 
     
     
       22. A compiler system comprising:
 a dynamic random access memory; 
 a boundary locator to identify a current boundary of a static data region in the dynamic random access memory; and, 
 a heap placement engine to set a lower boundary of a managed heap at an address in the dynamic random access memory located a safeguard distance above the current boundary. 
 
     
     
       23. A system as defined in  22  wherein the safeguard distance is larger than a maximum growth amount of the static data region. 
     
     
       24. A machine accessible medium containing instructions which, when executed, cause a machine to:
 identify a current boundary of a static data region in a memory; and 
 set a lower boundary of the managed heap at an address located a safeguard distance above the current boundary of a static data in memory. 
 
     
     
       25. A machine accessible medium as defined in  claim 24  wherein the safeguard distance is larger than a maximum growth amount of the static data region. 
     
     
       26. A method of constructing a pointer to an address in a managed heap comprising:
 loading an offset portion of the address; 
 appending a predetermined value to the offset to generate an intermediate address; and 
 combining the intermediate address with a predetermined base address of a managed heap. 
 
     
     
       27. A method as defined in  claim 26  wherein the predetermined base comprises sixteen bits of the address. 
     
     
       28. A method as defined in  claim 26  wherein combining the intermediate address with the predetermined base address comprises loading the base into a first predetermined portion of a register. 
     
     
       29. A method as defined in  claim 26  wherein loading the offset portion comprises loading the offset portion into a second predetermined portion of the register. 
     
     
       30. A method as defined in  claim 26  wherein appending the predetermined value comprises shifting the offset. 
     
     
       31. A method as defined in  claim 26  wherein the predetermined value is dependent on the memory allocation structure.